One nugget providing food for thought among the less technical parts of this handbook are the tips for reaching consensus (e.g., on a plan of action to correct a quality problem). Here is the list (from p. 154), along with some comments from me:

Use a facilitator. (Often a good team leader will do fine in this role.)

Take good notes. (Include issues discussed, main points pro and con, decisions reached.)

Balance power. (If this is apt to be ticklish, an outside facilitator may indeed be necessary.)

Make sure there is enough time. (If necessary, arrange a follow-up meeting, but with a clear idea of how the group will progress to a decision.)

Search for alternatives that meet the goals of all members. (This may involve discussing the interests behind goals in order to determine where there is flexibility.)

Encourage. (The atmosphere of the discussion must be one in which people can speak freely. Ground rules should make clear that civility is the order of the day.)

Be open to new ideas, but don't change your mind simply to avoid conflict or speed up the decision. (As far as possible, use concrete evidence to resolve disputes about likely outcomes of alternative proposed solutions.)

Don't just argue for your point of view. (Or, as I would put it, explain your rationale clearly, and refer to concrete evidence in support of your position. Participate in exploration of how to incorporate useful aspects of alternative plausible solutions into the final chosen solution.)

Seek out differences of opinion. Have people play devil's advocate. (Extremely important for avoiding groupthink.)

Bear in mind that consensus decision-making is only appropriate in certain situations. The Six Sigma Pocket Guide specifies seeking consensus for decisions that are high impact, high consequence (I assume this has more of a political flavor than "high impact," which presumably refers to technical aspects of the decision), emotionally charged, full of controversy (e.g., over who will be affected how by the decision reached), and characterized by a wide diversity of opinion (e.g., over decision criteria and the weights to assign them).